Staining Concrete

Until Labyrinth Enterprises developed its proprietary polymer concrete technique (see polymer), the most common way for the decorative concrete industry to address a pattern as complicated as a labyrinth would be to make a stencil and sand blast the pattern into the concrete. It would then be stained, typically with an acid stain which reacts chemically with the concrete. These days, there is a wider selection of stains, including water-based, soy-based, and dyes. However, working with stains is very challenging, as is typified by the email exchange I had with an unhappy client of our competitor, a major labyrinth company on the East Coast that has a high visibility on the search engines. I have made slight edits to protect the identities, for the sake of privacy. Note that the problem of appearance is actually the way stains usually are, which is why we like the opacity of polymer concrete.


Dear Robert,

I'm asking for your help. I had the pleasure of meeting you in 2003 during my first labyrinth gathering in Baltimore, Maryland. At that time, our planning committee was involved in conversations with D____ T_____, of The L_____ C_____, to construct a Chartres-replica, concrete labyrinth at ________ University campus in R______. You may recall our conversation and excitement about the possibility of you and D____ working on this project together. As it turned out, D____ was opposed to that idea. Since D____ is located in our region and we had already begun discussions with him, the planning committee decided that we should proceed by contracting The L_______ C______. We held the belief that D____ is one of the few qualified individuals doing this type of work in the nation.

Unfortunately, we are very disappointed with the finished product. Without going into great detail, I will tell you that D____ was unable to produce the desired effect he had promised. He too was admittedly disappointed with the outcome, yet expected full payment for an inferior job. Once paid in full, he would then be willing to attempt improvements (for an additional $7,000 - $10,000 with no guarantee that another approach would work). Obviously, we are no longer interested in continuing to do business with The L________ C______ and have parted ways with D____. We now desire to move forward and complete our labyrinth project by exploring all options and contracting someone to improve its appearance ... my hope would be that you are that person. Our campus and local communities have embraced this labyrinth and will continue to do so. We are committed to finding the best solution and getting the work done before the pattern fades away completely.

Robert, I would so appreciate your guidance and direction. At the very least, would you consider participating in a conference call with myself and our assistant director to discuss this? Of course, we will pay your consultation fee. Then, if you are interested in working with us, we could discuss your availability and costs.

I'll look forward to hearing from you,




Thanks for the note. Concrete stain is very unpredictable. That's one reason why we developed a superior system with polymer concrete. It would be possible for us to convert the labyrinth from stain to polymer concrete, but the cost would be almost as much as a new labyrinth (less, of course, the cost of installing new concrete). We would mask off the pattern, sandblast away the stained lines, and shoot the lines with polymer concrete. The color would be opaque and very durable. Our fee would be $14,000 plus the cost of having someone do the sandblasting (we don't have that kind of equipment or experience). In addition, there would be expenses for travel, lodging, and meals. It could amount to $20,000 before you were all done. Of course, it would be very durable and low-maintenance.

In D____'s defense, I hope he has in his contract that stain is unpredictable. The client can be promised green, but it might come out brown. And it will be very mottled looking, perhaps somewhat thin. The contractor can do a few things to try to get the specific results, but in the end, you get what you get (especially if D____'s subcontractor was the lowest bidder). That's why polymer concrete is so much more predictable. While there is still a small range of color variation, as conditions change by the hour (temperature, humidity, etc.). In the end, however, it is quite satisfactory.

Sorry to hear about your problems. Here's a possible way for you to fix it yourselves. The stain that D____ used was a reactive stain, that reacts chemically with the concrete itself. Colors are usually rather limited, normally to natural colors such as browns and beiges. That's because the color is made from minerals, hence the earth tones. Now, in the concrete world, concrete "art" is very popular. The pictures have brilliant colors, fairly opaque. They come from water-based stains that are not reactive. That's important, because the reactivity has already been used up by the current stain. These stains are essentially painted on. They then have to be well sealed for protection (and continuously sealed every couple of years). .

First, however, you would have to remove the sealer covering the current stain. (I am presuming the problem is only with the lines, not the paths). There are chemicals for doing that. It would have to be done carefully, so as not to damage the paths. Once the sealer is off, then a water-based stain could be applied. Some brand names are Nature Stain, New Century Coatings, and Smith Paints. Then, after carefully hand-painting the stain in one or two coats, you would hand-paint two or more coats of sealer.

We are not available for such work. (Our cost would be $20,000 due to all of the labor, so you might as well get the polymer concrete). So, all in all, D____'s repair cost is somewhat reasonable, if he solves your problem. You could ask him to do this last method (remove sealer, water-based stain, re-seal), at his $10,000 price. If he agrees, that would be a bargain.

That's about the best news I can give. Sorry.

Best wishes,



Dear Robert,

I very much appreciate you taking the time to respond to our dilemma by offering your insight and advice. I've shared this information with our project director and others. We are now seeking guidance from area professionals who specialize in all aspects of concrete. I have every confidence that through our good intentions, vigilance, and prayer our labyrinth will become the sacred work of art it is destined to become.

Robert believe me, D____ has no defense. You cannot imagine the heartache, frustration and disappointment he has caused. Unfortunately and unbelievably, he walked away and left us with a mess. The paths of circuits 9, 10, 11 and the center flower are completely colorless. The rest of the path is a mish-mash of "here some stain of one shade, there some stain of another shade, and mixed throughout with areas of absolutely no stain. Honestly, we understand color variation and a mottled look; we actually wanted something that resembled an "old world, ancient look" in deep, rich, earthy tones as opposed to something that was noticeably brand new. D____ created two concrete [samples] that looked absolutely gorgeous with the coloring we selected. Unfortunately, his attempt to stain the circular slab wasn't even close to what we were shown. The stain did not penetrate the concrete. The lines distinguishing the paths were meant to be a deep, dark brown (almost black). In some spots they have faded to a pale gray shade. D____ also added aggregate stone to the cement in order to give texture and interest to the finished look. Well, that didn't happen. When it took him about two hours to sandblast a 12" square, I guess he decided it was way too much work and did a real half-assed job from that point exposing a minimal amount of stone.

What is most upsetting to me is that I specifically asked D____ if he was going to be on-site for the entire project. He said absolutely, and yet, he was not here one time during the entire process of digging the foundation and pouring the concrete. He was supposed to have the job completed for us in April and didn't finish it until November with one excuse after another. He accused the subcontractor of not mixing the concrete according to his specifications. We contracted D____ to do the job. If he had been here overseeing the project as agreed upon, he could have made certain all was going according to his plan.

Lastly, D____'s customer service skills are greatly lacking. We had a horrible experience dealing with The L________ C______. End of story.

Our goal is to bring this to closure by mid-Fall. Once again, thank you and please keep us in your prayers!





I have seen photos of stained labyrinths made by The L________ C______ which also showed some light areas such as you describe. I still think this is typical for stain. The problem with samples is that the maker labors over a sample of one square foot, getting a result that is virtually impossible to repeat on a larger scale. It's a common mistake in the concrete business, and not an attempt to defraud anyone. It is, however, a formula for unhappy clients such as yourselves.

I just returned from a four-day trip to California to repair a polymer concrete labyrinth that we made earlier this year.In five years, this is our first problem. The issue, which was also about color, defied the laws of concrete technology. I was able to do very little. When I left it wasn't much better than when I had arrived. The client is not happy,not are we. We plan to return in October when we are again in California with our crew, hopefully finding a solution by then. We will do everything reasonable, at our expense, to resolve the problem. However, if we don't find one, we must fall back on the fact that we installed the labyrinth in good faith, in the same way as all of our others, which have been successful and none of which have ever had this problem. We would not be in a position to remake the entire labyrinth without a financial consideration. So, I have some sympathy for D____, whom I know is very busy. (As deficient as his service may be, he is very strong at marketing.) It's too bad that you were not in a position to switch to polymer concrete when you had a chance. I can only hope that my clients will be as faithful to me as you were to D____.

Tell your concrete contractor that Jasco makes a Sealer and Adhesive Remover that will easily remove the sealer (although with some considerable mess). There is also a soy gel on the market (the brand name escapes me) that may do the same, with less toxicity. They could then attempt to use an opaque stain such as New Century Coatings makes. In fact, their stain has sealer mixed right in with it, making it a one-step process. I think you would get a pretty good result. Please stay in touch and let me know how it comes out. Before and after photos would be instructional, as well as good notes about products and techniques. Perhaps there will be instances in which such repairs will be needed in the future for others who own stained labyrinths.

Best wishes,